Contribution of Lewis blood groups molecules in biofilm formation of Pseudomonas aeruginosa isolated from atopic dermatitis patients.

Biofilm formation is a mechanism for bacterial community defense against insults including antibiotics .In this report we evaluated the potency of Pseudomonas aeruginosa(P. aeruginosa) isolates from atopic dermatitis patients skin as well as stool to colonize different Lewis types saliva , manifested by biofilm formation . The bacteria were cultured on tryptose soy broth .96-well polystyrene plate were used .Coating with heat inactivated Le (a), (b) and (c)saliva was performed. Biofilm intensity was measured using crystal violet stained films compared to non –saliva coated situation. The results showed a superior capability of most isolates to form biofilm on Le (a) followed by Le (b) saliva. The highest binding mean was for isolate ( 4). Le (a) saliva binding (mean ± SD was 0.66± 0.25 for test compared to 0.21± 0.04 for control non coated wells) , p=0.04,cl=0.041-0.864. Other isolates demonstrated variable degree of biofilm formation on this substrate .In contrast to Le (c) saliva, Le (b) saliva demonstrated weak biofilm formation . We conclude that, among atopic dermatitis patients skins, P. aeruginosa Lec (A) or Lec (B) lectins might be involved in colonization in such patients. Key Words:- Lewis blood groups – Pseudomonas aeruginosa -atopic dermatitis– Biofilm

Biofilm formation by Staphylococcus aureus isolation from atopic dermatitis patients on defined Lewis types saliva

Bacteria adherence and biofilm formation vary depending on the strain of microorganism as well as the substrate.Here, we evaluated the ability of different isolates of Staphylococcus aureus (S. aureus), isolated. from atopic dermatitis patients skin and stool to form a biofilm on different Lewis types saliva, including Le (a) , (b) ,(c) and Le a+b+ saliva. S. aureus isolates were cultured on tryptose soy broth.The bacteria were used to form a biofilm on 96- well flat bottom Microtitration plate that was coated with the respective, optimally diluted, processed saliva of Lewis blood groups (a),(b),(c) and Le a+b+.The intensity of biofilm formation was assessed by measuring the biofilm-associated optical density reading of bacterial bound dye. The results indicated a superior ability of biofilm formation on Lewis(a) saliva type.The highest binding gave a mean of 1.25 ± 0.39 compared to biofilm formation on non – coated wells that showed a mean of 0.23 ± 0.016(P=0.01, CL= 0.390 – 1.635). On the other hand, however, a variable degree of binding to Le(b) saliva was demonstrated for the isolates. The isolates didn’t demonstrate binding on Lea-b-(Lec) and Le a+b+ -(Led) saliva. We conclude that biofilm formation on Lewis types saliva of the atopic dermatitis bacterial isolates requires Le(a) in a ligand – receptor-based system for biofilm establishment.

Biofilm formation by Staphylococcus aureus Isolation from atopic Dermatitis Patients on Defined Lewis Types saliva

Bacteria adherence and biofilm formation vary depending on the strain of microorganism as well as the substrate.Here, we evaluated the ability of different isolates of Staphylococcus aureus (S. aureus), isolated. from atopic dermatitis patients skin and stool to form a biofilm on different Lewis types saliva, including Le (a) , (b) ,(c) and Le a+b+ saliva. S. aureus isolates were cultured on tryptose soy broth.The bacteria were used to form a biofilm on 96- well flat bottom Microtitration plate that was coated with the respective, optimally diluted, processed saliva of Lewis blood groups (a),(b),(c) and Le a+b+.The intensity of biofilm formation was assessed by measuring the biofilm-associated optical density reading of bacterial bound dye. The results indicated a superior ability of biofilm formation on Lewis(a) saliva type.The highest binding gave a mean of 1.25 ± 0.39 compared to biofilm formation on non – coated wells that showed a mean of 0.23 ± 0.016(P=0.01, CL= 0.390 – 1.635). On the other hand, however, a variable degree of binding to Le(b) saliva was demonstrated for the isolates. The isolates didn’t demonstrate binding on Lea-b-(Lec) and Le a+b+ -(Led) saliva. We conclude that biofilm formation on Lewis types saliva of the atopic dermatitis bacterial isolates requires Le(a) in a ligand – receptor-based system for biofilm establishment.